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
Answer:
x = 24
Step-by-step explanation:
Firstly, isolate x by adding 2 to both sides.
9 = 3/8x
Then, multiply 8 to both sides.
72 = 3x
Then, divide both sides by 3.
24 = x
Between 2 and 3, should be somewhere before .5
Answer:
Step-by-step explanation:
When x =3 y=-1
X =2 y =0
X=0 y =3
X = -1 y=6
So c g d f true