(1) y = 7x , (2) y = 11x , (3) y = 9x , (4) y = 28x
given y varies directly as x then y = kx ( k is the constant of variation )
(1) find k using the given conditions k = [tex]\frac{y}{x}[/tex] = [tex]\frac{63}{9}[/tex] = 7
equation is y = 7x
(2) k = [tex]\frac{121}{11}[/tex] = 11
equation is y = 11x
(3) k = [tex]\frac{36}{4}[/tex] = 9
equation is y = 9x
(4) k = [tex]\frac{224}{8}[/tex] = 28
equation is y = 28x
