Answer:
x=1, y=7
Explanation:
the system is:
{-5x+2y=9
{y=7x
first, simplify the expression:
{-5x+2y=9
{-7x+y=0
then, multiply both sides of the equation by -2:
{-5x+2y=9
{14x-2y=0
then, eliminate one variable by adding the equations:
9x=9
divide both sides by 9:
x=1
substitute the value of x into the equation:
-7x+y=0
-7(1)+y=0
solve the equation:
y=7
the answer is:
(x,y)=(1,7)
