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If y varies as directly as the square of x, and y = 75/8 when x = 5, find y when x = 2

Respuesta :

Step-by-step explanation:

y varies as x^2

y=75/8

x=5

x^2=5^2=25

y=kx^2

k= constant

75/8=25k

cross multiply

8*25k=75

200k=75

k=75/200=15/40=3/8

therefore k=3/8.

equation bonding x and y =

x=3/8y

x=5. 5=3/8y

3=40y. therefore y=3/40.

when x is 2

2=3/8y

16y=3

y=3/16