V=B+15
V+2B=180
Therefore:
3B+15=180
B=55
V=70
Check:
V+2B=180
70+2(55)=180
70+110=180
180=180. Checks.
Answer:
- width: 18 in
- length: 27 in
Step-by-step explanation:
The relations between length (L) and width (W) are ...
W +9 = L
LW = 486
Substituting gives ...
(W+9)W = 486
W^2 +9W -486 = 0 . . . put in standard form
(W +27)(W -18) = 0 . . . . factor
W = 18 . . . . the positive solution
The width of the rectangle is 18 inches; the length is 27 inches.
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<em>Comment on factoring</em>
There are a number of ways to solve quadratics. Apart from using a graphing calculator, one of the easiest is factoring. Here, we're looking for factors of -486 that have a sum of 9.
486 = 2 × 3^5, so we might guess that the factors of interest are -2·3² = -18 and 3·3² = 27. These turn out to be correct: -18 +27 = 9; (-18)(27) = -486.
Answer:
p<4
Step-by-step explanation:
4p+2< 2(p+5)
Distribute: 4p+2<2p+10
Subtract 2 from both sides: 4p<2p+8
Subtract 2p from both sides: 2p<8
Divide and we get: p<4