Question

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Answer 1

hey
f(a)=9
means 4a-5=9 <--solve for a

Answer 2

and f(b)=5
means 4b-5=5 <--solve for b

Answer 3

then f(a+b)=4(a+b)-5

Answer 4

actually easier to solve for 4a and 4b :)

Answer 5

for a i got 30 and for b i got 15 and the answer is 19 so im not sure what i did wrong

Answer 6

yes I don't know how you get 30 and 15 :(

Answer 7

but 4a-5=9
to solve for a
add 5 on both sides
4a=14

Answer 8

i did 4(9) - 5

Answer 9

oh no

Answer 10

f(a)=9 doesn't means f(9)=a

Answer 11

to find when f(a)=9
you need to solve 4a-5=9 for a

Answer 12

14/4?

Answer 13

yep

Answer 14

and solve the other equation 4b-5=5

Answer 15

10/4

Answer 16

the simplify :
\[f(a+b)=4(a+b)-5 =4(\frac{14}{4}+\frac{10}{4})-5\]

Answer 17

ohh got it so 19 thanks so much!

Answer 18

np