9514 1404 393
Answer:
1e. 2t² +8t -6
2h. a² +2ab -3b²
3b. 8r +4
4b. 6x +4y -11
5b. e -3
Step-by-step explanation:
1e. Combine like terms.
(3t² +3t -6) +(-t² +5t) = t²(3 -1) +t(3 +5) -6
= 2t² +8t -6
__
2h. (2a² +3ab -4b²) -(a² +ab -b²)
Use the distributive property to eliminate parentheses. Note that all signs change in the second set of parentheses.
= 2a² +3ab -4b² -a² -ab +b² = a²(2 -1) +ab(3 -1) +b²(-4+1)
= a² +2ab -3b²
__
3b. The hash marks indicate sides of the same length. The perimeter is the sum of all side lengths.
P = (4r -2) +2(2r +3)
P = 4r -2 +4r +6 . . . . . . eliminate parentheses
P = 8r +4 . . . . . . . . . . . . combine like terms
__
4b. (3x +4y) +(5x -8) -(2x +3)
Note that the distributive property changes the sign of all terms in the last parentheses.
= 3x +4y +5x -8 -2x -3 . . . . eliminate parentheses
= x(3+5-2) +y(4) +(-8-3) . . . group like terms
= 6x +4y -11
__
5b.
Bill's age - Erin's age = (2e-3) -(e) = e -3
The difference in their ages is (e -3).
