Question

If y varies directly with x and y = -7 when x = -1, find x when y = -84.
Answer

84

7

-12

Answer 1

try dividing 84 by 7 to find the ratio

Answer 2

-12?

Answer 3

-84 divided by -7 equals +12

+12 is your ratio

you need to put the x value you know into the ratio

-1 times 12 equals -12

so thats the answer but you need to remember to use the ratio to find it otherwise you can end up with the wrong sign or if x had been 2 you would have a completly different answer.

Answer 4

Write the slope-intercept form of the line which passes through (4, 2) with a slope of 1/2.
Answer

y = 1/2 x + 2

y = 1/2 x

y = 1/2 x + 4