Z varies directly as x². If z=8 when x=2, find z when x=7

98

Step-by-step explaination:

For this question, it is a direct variation. Hence, the equation would be formed accordingly, and the constant k would also be used.

z varies directly as x²

z = kx² where k is the constant

z = 8

x = 2

Putting the figures in the equation, we have

8=2² (k)

8 = 4k

Dividing both sides by 4, we have

k = 8/4

k = 2

Solving for z now, we substitute k with 2. And x with 7

z=kx²

z = 2 (7²)

z = 2 (49)

z = 98

If it were indirect variation, the constant would have been 1/k. We also have other types of variation, Indirect variation, partial variation and joint variation.