25mm is the answer if its not tell me
Peter's account is 910-40x, and Marla's account is 470-2x. This is a system, so you must find the number that makes both equations end up with the same number. Basically trial and error. Here is what I did:
Let's try the number 10. 910-400=510 and 470-20=450. I need a higher number.
Let's try 13 next. 910-520=390 and 470-26=444. Now the number has to be lower.
Let's try 12. 910-480=430 and 470-24=446. Close, and a little lower.
11.5 is too low, and 11.7 is too high. 11.6 has Equation 1 at 446 and Equation 2 at 446.8. Very close!
It is somewhere around 11.6. I hope that this can give you a start in figuring it out, because I don't believe in giving the complete answer, because then you do not learn anything from it.
Answer:
31 units
Step-by-step explanation:
When the figure is a parallelogram, opposite sides have the same measure:
AD = BC
3x +7 = 5x -9 . . . . . . substitute given expressions
16 = 2x . . . . . . . . . . . add 9-3x
8 = x . . . . . . . . . . . . . divide by 2
Use this value of x in the expression for AD to find its required length:
AD = 3(8) +7 = 24 +7
AD = 31 . . . . units
The length of segment AD must be 31 units for ABCD to be a parallelogram.
