Question

What is the value of x and y if 21x+7y=42 and -5x+5y=10 are equal

Answer 1

-5x/5 +5y/5=10/5=2

y-x=2

y=x+2

21x+7*(x+2)=42

21x+7x+14=42

28x=42-14

28x=28

x=1

y=1+2

y=3

Explanation: