Answer:
inequality notation: x > -1
interval notation (-1, ∞)
.05c+.3s=10.25, c+s=100, c=100-s (c is for cards that don't sing and s is for those that do :P)
.05c+.3s=10.25 and c=100-s makes the equation become:
.05(100-s)+.3s=10.25
5-.05s+.3s=10.25
.25s=5.25
s=21, and since c=100-s
c=79
So she bought 21 of the more expensive singing cards...
Answer:

Step-by-step explanation:
(-⁹/13) × (-⅔)
³/13 × 2
= ⁶/13
Answer:
Step-by-step explanation:
a) Let the width = w
Two times its width = 2*w = 2w
9 inches less than 2w = 2w - 9
Length = 2w - 9
Area of rectangle = length *width = 180 square inches
(2w - 9 ) * w = 180
2w*w - 9*w = 180
2w² - 9w - 180 = 0
b) sum = -9
Product= -360
Factors = -24 , 15 {15 *[-24] = -360 and 15 + (-24) = -9 }
2w² - 9w - 180 = 0
2w² - 24w + 15w - 180 = 0
2w(w - 12w) + 15(w - 12) = 0
(w -12) (2w + 15) = 0
{Ignore 2w + 15 = 0 as measurements cannot be a -ve value}
w - 12 = 0
w = 12 inches
l = 2w -9
= 2*12 - 9
= 24 - 9
l = 15
length = 15 inches
Width = 12 inches
c) Perimeter = 2 *(length + width)
= 2*(15 + 12)
= 2 * 27
= 54 inches
(24,18)(28,21)
slope(rate of change) = (21 - 18) / (28 - 24) = 3/4 <==