Verified answer

1. When a = -5 and b = 2; Evaluate 3a – 4b

First: replace "-5" with the a-varaible and "2" with the b-variable in the expression...

3(-5) - 4(2)

- 15 - 8

= - 23

2. List the "like" terms in the following groups of terms.

-5t, -3st^2, 3s^2t, -7st^2, 2st^2, -5s^2

"Like" terms: -3st^2; -7st^2 and 2st^2

3. Evaluate: (-10)(-9) - 5

First: Use PEMDAS < (), exponents, multiplication, division, addition & subtraction...

90 - 5

= 85

Well, I'm not sure what you're saying in the detail part of your question, but if a= -5 and b= 2, for the equation or 3a-4b, the answer would be -23:

3(-5) - 4(2)

-15 - 8

=-23

ok if a=-5 b=2 then u would change the equation. replace the variables with the value. so instead of it being 3a, it would be 3(-5)-4(2). then multiply. 3times -5 = -15. -15-4(2)

then do 4 times 2=8....then ur left with -15-8. which would be the same thing as adding 15 and 8 and just putting a negetive sign next to it.

for the like terms things,match up the variables. example : -3st2 matches -7st2..get it?

3(-5)-4(2)=-15-8

= -23

im assuming for the 2nd problem, the "2" after a variable is supposed to be a square

(-5t) (-3st2, -7st2, -2st2, so that equals -12st2) (-5s2) (3s2t)

90-5=85

plug in the values of a and b in to the equation like 3 (-5) - 4(2) and solve from there doing multiplication first and subtraction second

3a - 4b

3(-5)= -15

(-4)2= -8

-15 - 8 = -23

(-10)(-9) - 5

(-10)(-9) = 90

90 - 5 = 85

initially you should cancel out the brackets: 4x2a=8a the you do the second one area of the brackets: 4x-b=-4b Then outdoors the brackets you should minus the 5a because it says -5a: so the equation you've is 8a-4b-5a the merely correct answer you get is 3a-4b because 8A and -5A are person-friendly multiples

=-15-8=-23

-450

the first one is- (-23)

2nd one -idk

third one- 85

i suck at math