Question 963807
A=Ashraf's age; M=mother's age
M-10=4(A-10)
M-10=4A-40
M=4A-30 Use this to substitute for M below.
M+10=2(A+10)
M+10=2A+20
M=2A+10 Substitute for M from above.
4A-30=2A+10 Add 30 to each side
4A=2A+40 Subtract 2A from each side.
2A=40 Divide each side by 2.
A=20 ANSWER: Ashraf is 20 years old.
CHECK:
M=4A-30=4(20)-30=80-30=50 Mother is 50 years old.
M+10=2(A+10)
50+10=2(20+10)
60=2(30)
60=60