four times daphne's age plus five times isaac's age adds up to 57. also, isaac's age is 11 less than twice daphne's age. how old

Question

SOVA2 [1]

3 years ago

15

four times daphne's age plus five times isaac's age adds up to 57. also, isaac's age is 11 less than twice daphne's age. how old

is isaac?

Mathematics

1 answer:

Talja [164] · Answer 1 · 2022-08-08T01:42:03+03:00

Talja [164]3 years ago

5 0

4d + 5i = 57
i = 2d - 11

4d + 5(2d - 11) = 57
4d + 10d - 55 = 57
14d = 57 + 55
14d = 112
d = 112/14
d = 8 <== Daphne's age

i = 2d - 11
i = 2(8) - 11
i = 16 - 11
i = 5 <==Isaac's age