A = l × w. Substitute 72 into A and fill in the rest of the equation.
w = l - 1. Plug l - 1 into w
72 = l × (l - 1). Multiply l by (l - 1)
72 = l^2 - l. Subtract 72 from each side.
0 = l^2 - l - 72. Factor.
0 = (l + 8) (l - 9). Set each term equal to zero.
(l + 8) = 0. Subtract 8 from each side.
l = -8. Length cant be a negative number so let's try the other term.
(l - 9) = 0. Add 9 to each side.
l = 9. The length is 9.
Earlier we stated that the width is one less than the length, therefore, the width is 9 - 1 = 8.
The width is 8 units.
Answer:
7) 230mm
8) 98m
Step-by-step explanation:
7)
7x+8+6x+6+9x-4 =22x+10
if x is 10 mm, 22(10)+10 =230mm
8) perimeter of rec =2( l + w )
=2 ( 2x-5+2x+6 ) = 8x + 2
if x is 12 metres, 8(12)+2 =98m
Answer:
(21)+(6) is an equivalent expression
Step-by-step explanation:
(7x3)2(x3)
(21)+(6)
We can set up a system of equations to solve this.
120b + 90d = 270
60b + 110d = 265
To cancel out b, first make the b terms equal.
60b · 2 + 110d · 2 = 265 · 2
120b + 220d = 530
Now subtract the equations.
120b + 90d = 270
-120b + 220d = 530
---------------------------
-130d = -260
Solve for d.
-130d/-130 = -260/-130
d = 2
Now put the value of d in one of the equations.
60b + 110d = 265
60b + 110 · 2 = 265
60b + 220 = 265
60b + 220 - 220 = 265 - 220
60b = 45
60b/60 = 45/60
b = 0.75
Each candy bar sells for $0.75
Hope this helps! :)
