Answer:
20
Step-by-step explanation:
The first equation is 50 - 2x (because you start with $50 and subtract 2 for each 30 day period)
The second equation is 40-1.5x
Set them equal to each other: 50 - 2x = 40 - 1.5x
Solve for x:
50 - 2x = 40 - 1.5 x
+2x +2x
-----------------------
50 = 40 + 0.5 x
-40 -40
-------------------
10 = 0.5 x
20 = x
So there will be 20 30-day periods until the cards will be equal in value.
Check: After 20 periods, 50 - 2(20) = $10 left
40 - 1.5(20) = also $10 left
Perimeter is the sum of all the sides. One length equals (x+4) so both of the lengths will equal 2(x+4) = 2x+8. One width is (2x-7) so both will equal 2(2x-7) = 4x-14.
we can write this into an equation like so:
2x+8+4x-14=42
6x-6=42
6x=48
x=8
Then we substitute 8 back into the equations for the lengths of the sides.
8+4= 12 so the length is 12cm
2x8= 16, 16-7=9 so the width is 9cm
Answer: give more info
Step-by-step explanation: i think this deserves a brainlyest
