Question

Can someone help me out?
2. Evaluate the expression for a = –1 and b = 5. Show your work.
5a – 7b + b^2

This is how i solved it i'm just seeing if i did it right or if i messed up somewhere throughout the problem

5+ -1 -7(5) + (5)^2
-35 25
4+ -35 25
4+ -35 = -31
-31+ 25 = -6

Answer 1

You messed up.

Answer 2

\(\sf\Large 5a – 7b + b^2\)

where
\(\sf\Large a=-1 \\\sf\Large b=5\)

Answer 3

So simply just plug in the numbers:

\(\sf\Large 5(-1) -7(5)+(5)^2=?\)

Answer 4

Remember, it's multiplication we are doing. Not addition or subtraction.

Answer 5

Alright is this correct

5+( -1) -7(5) + (5)^2
-35 25
- 5 -35 25
-5+ -35 = 40
-40+ 25 = 15

Answer 6

almost correct,

but

\(\sf\Large -40+25 = \color{red}{-}15\)

because

\(\sf\Large -40+25 = 25-40\)

Answer 7

5+( -1) -7(5) + (5)^2
-35 25
- 5 -35 25
-5+ -35 = -40
25 + -40 = 15
How about now?

Answer 8

you have all the steps correct except the last one

\(\sf\Large 25+ (-40) = -15\)

\(\sf\Large -40 + 25 = -15\)

It's \(\bf \color{red}{-}\)15

It's a negative 15...

Answer 9

Oh didn't notice that >~< I'm sorry.

Answer 10

It's ok, we should learn from our mistakes. :)

And Welcome to OpenStudy! @Ashtaroth

Answer 11

Thanks. I think this place is going to help me big time with my algebra.

Answer 12

Could you help me with another?

Answer 13

sure close this question and post another question :)