Answer:
sister is 52
bob is 24
Step-by-step explanation:
Let S = sisters age and B = Bob's age
Bob's sister is 4 years older than twice Bob's age:
mathematically : S = 4 + 2B ..... eq1
the sum of their ages is 76
mathematically : S + B = 76 .... eq 2
substituting eq 1 into eq2,
S + B = 76
(4+2B) + B = 76
4 + 3B = 76 (subtract 4 from both sides)
3B = 76 -4
3B = 72 (divide both sides by 3)
B = 72/3 = 24 (answer)
substitute value of B into equation 1
S = 4 + 2B
S = 4 + 2(24)
S = 4 + 48
S = 52 (answer)
