Question

Solve the system of equations 6, x, plus, 7, y, equals, minus, 136x+7y=−13 and x, plus, 3, y, equals, 7x+3y=7 by combining the equations.
Below, two sets of the two equations are shown. The first set has input boxes in front of each equation to put a number to multiply it by. When you enter a number, the corresponding equation below changes to be the result of the multiplication. Under the second set, a resulting equation is shown with input boxes for the coefficients and constant. Then, there is a "try" button. When you press the try button, if your answer is correct, it will be placed on the page and a new question will appear with a new input box. This process will continue until the final answer area appears with the submit button.
left parenthesis, 6, x(6x plus, 7, y+7y equals= minus, 13, right parenthesis−13)
left parenthesis, x(x plus, 3, y+3y equals= 7, right parenthesis7)
6, x6x plus, 7, y+7y equals= minus, 13−13
xx plus, 3, y+3y equals= 77
0
0xx plus+
0
0yy equals=

Answer 1

Solve by elimination.

Multiply the second equation x + 3y = 7 by −6:
−6x − 18y = −42.

Add this to the first equation 6x + 7y = −13:
(6x − 6x) + (7y − 18y) = −13 − 42 → −11y = −55 → y = 5.

Substitute y = 5 into x + 3y = 7:
x + 15 = 7 → x = −8.

Solution: (x, y) = (−8, 5).