here it the question that i can't figure out...
A glass and mirror store is selling mirrors and frames. The store charges 10 Cents for each square inch of mirror, and 25 cents for eack linear inch of frame.
If there was a mirror that measured 40 inches on one side, what would the other measuremenr be if the price was $85?
thanks for the help
2007-08-28 04:13:56 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Let x be the measurement you're looking for (in inches).
The area of the mirror is 40x square inches. At 0.10$ per square inch, this will cost 4x dollars.
The perimeter is (80 + 2x) inches. At 0.25$ per square inch, the frame will cost (20 + 0.5x) dollars.
The total cost of the mirror is therefore
4x + 20 + 0.5x = 85
Solve away.
2007-08-28 04:33:52 · answer #1 · answered by Anonymous · 0⤊ 0⤋
.25(80 + 2x) + .1(40x) = 85, so 20 + .5x +4x = 85, and 4.5x = 65, so x = 14 4/9 in.
2007-08-28 11:21:51 · answer #2 · answered by John V 6 · 0⤊ 0⤋
0.25(2x + 2y) + 0.1xy = 85
0.25(2x + 80) + 4x = 85
0.5x + 20 + 4x = 85
4.5x = 65
x = 14.4 in.
Ans. 14 (two significant figures)
2007-08-28 11:21:13 · answer #3 · answered by gebobs 6 · 0⤊ 0⤋