X - the number
3x - 7 = -4 |add 7 to both sides
3x = 3 |divide both sides by 3
x = 1
Answer:
Step-by-step explanation:
Present age of Barry = b
Present age of sister = s
Barry is 8 years older than his sister means if we subtract 8 from present age of Barry both will be of equal age
s=b-8 ............(1)
In 3 years means we have to add 3 in their present age
s+3=b+3
then
he will be twice as old as
2(s+3)=(b+3
2s+6=b+3
2s=b+3-6
2s=b-3...............(2)
Put the value of s from (1) to (2), we have
2(b-8)=b-3
2b-16=b-3
2b-b=-3+16
b=13
Put the value of b in (1)
s=13-8
s=5
Present age of Barry = b = 13
Present age of sister = s = 5
X+y=57
y=x+15
x+x+15=57
2x=42
x=21
y=21+15
y=36
Answer:
8.25 is the answer.
Step-by-step explanation:
Hope this helps!
