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1. X is partially constant and partially varies direct as Y when X=16, Y=2 When X=10, Y=5 (i)find the equation connecting X and Y (ii) X when y=8 (iii) Y when X=12.
2. In a class of 80 students, 30 offer Agric, 35 offer Agric, 40 offer chemistry. Given that 15 of them offer Agric and bio, 20 offer bio and chem. and 25 offer Agric and chem. (i)find the intersection of all the subjects. (ii) only 2 subjects (iii)chem & bio.

Very easy question.

Kylekent59:
Very easy question.

Ar swear very easy kwesion

Timothy245:
1. X is partially constant and partially varies direct as Y when X=16, Y=2 When X=10, Y=5 (i)find the equation connecting X and Y (ii) X when y=8 (iii) Y when X=12.
2. In a class of 80 students, 30 offer Agric, 35 offer Agric, 40 offer chemistry. Given that 15 of them offer Agric and bio, 20 offer bio and chem. and 25 offer Agric and chem. (i)find the intersection of all the subjects. (ii) only 2 subjects (iii)chem & bio.

Check ur question 2. 30 offer agric,35 offer agric. Wrong?

I) the equation is X= a + by, .... equation (0). where a and b are constants.
substituting values, x= 16 when y = 2 , and x= 10 when y=5
16 = a + 2b ................(1)
10 = a + 5b ................(2)
subtract equation (2) from (1) will give, 6= -3b. divide both sides by -3
therefore b = -2 ...
to get a, put b = -2 into equation (2), 10 = a + (-2×5), 10 = a -10 , 10+10=a, .. 20=a..
replace b = -2 and a = 20 into equation (0)

therefore the required equation is X = 20 - 2y ..... equation (3).

ii) x, when y = 8. just substitute into equation (3)
I.e x = 20 - 2 ( 8 )
x= 20 - 16
x= 4.
iii) same as above . y when x = 12
12= 20 - 2 y
12 - 20 = -2y
-8 = -2y
y = 4 ( divide both sides by -2)..
I hope it was helpful

[quote author=Matinoh post=63687770]I) the equation is X= a + by, .... equation (0). where a and b are constants.
substituting values, x= 16 when y = 2 , and x= 10 when y=5
16 = a + 2b ................(1)
10 = a + 5b ................(2)
subtract equation (2) from (1) will give, 6= -3b. divide both sides by -3
therefore b = -2 ...
to get a, put b = -2 into equation (2), 10 = a + (-2×5), 10 = a -10 , 10+10=a, .. 20=a..
replace b = -2 and a = 20 into equation (0)

therefore the required equation is X = 20 - 2y ..... equation (3).

ii) x, when y = 8. just substitute into equation (3)
I.e x = 20 - 2 ( 8 )
x= 20 - 16
x= 4.
iii) same as above . y when x = 12
12= 20 - 2 y
12 - 20 = -2y
-8 = -2y
y = 4 ( divide both sides by -2)..
I hope it was helpful
Thanks alot!

respect80:
Ar swear very easy kwesion

u Can't Solve It Noni

Kylekent59:
Check ur question 2. 30 offer agric,35 offer agric. Wrong?

that's how it was.

Timothy245:
u Can't Solve It Noni

Abeggi. Dis simple kwesion mtcheeeew

respect80:
Abeggi. Dis simple kwesion mtcheeeew

Then, prove urself by using another method to solve it.

Matinoh, tanx alot.

Timothy245:
that's how it was.

You should know there's a mistake in what you type. How will you repeat Agric twice, that 30 offer Agric, 35 offer Agric again? It should instead going by the next sentence in the question be: 30 offer Agric, 35 offer Bio.

Timothy245:
Then, prove urself by using another method to solve it.

lol, calm down. If he says it's simple that's because it actually is. he may feel he is insulting himself by just solving it.

some person just have this innate pride. I was once like that.

you already have a solution by Timothy245, I'd av provided one for you.

Timothy245:
Then, prove urself by using another method to solve it.

Don't worry I will solve it veeeeery soon