Answer:
C
Step-by-step explanation:
3x + 3y = -x + 5y
3x + x = 5y - 3y
4x = 2y
Divide both by 2
2x = y
(1,2) when x=1, y=2
2(1)=2 is a true statement
(2,4) when x=2, y=4
2(2)=4 is a true statement
Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present
It is something that you see often. In the problem it may say what is the area of a square that is 6in by 6in. The BY represent multiplication