Answer:
x=3 y=4
Explanation:
x+y=7; x + 2y =11
step: solve x + y = 7 for x:
x + y+ -y =7 + -y (add -y to both sides)
x = -y + 7
step: substitute -y + 7 for x in x + 2y =11:
x + 2y = 11
-y + 7 + 2y = 11
y + 7 =11(simplify both sides of the equation)
y + 7 + -7 = 11 + -7 (add -7 to both sides)
y = 4
step: substitute 4 for y in x = -y + 7:
x = -y +7
x = -4 + 7
x = 3 (simplify both sides of the equation)