Question

Please solve with steps
1) Add 3a (a – b + c) and 2b (a – b + c)
2)Subtract : 7p (3q + 7p) from 8p (2p – 7q)

Answer 1

Answer:

1. 3a²—2b²—ab+2bc+3ac

2. —33p²—77pq

Step-by-step explanation:

1. 3a(a—b+c) + 2b(a—b+c)

[open the brakets]

=3a²—3ab+3ac + 2ab—2b²+2bc

[substract like terms]

=3a²—2b²"—3ab+2ab"+2bc+3ac

=3a²—2b²—ab+2bc+3ac .

2. 8p(2p—7q) — 7p(3q+7p)

[open the brackets]

=16p²—56pq —[21pq+49p²]

[again open the bracket ]

=16p²—56pq—21pq—49p²

[subtract like terms]

="16p²—49p²"—"56pq—21pq" [—+—= —]

= —33p²—77pq /—33p²+77pq .

Answer 2

$\rm{2]\:8p\left(2p-7q\right)-7p\left(3q+7p\right)=16p^2-56pq-7p\left(3q+7p\right)}$

$\longrightarrow\rm{8p\left(2p-7q\right)-7p\left(3q+7p\right)=16p^2-56pq-21pq-49p^2}$

$\longrightarrow\rm{8p\left(2p-7q\right)-7p\left(3q+7p\right)=16p^2-49p^2-56pq-21pq=-33p^2-77pq}$