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.
correct answer is 0.0000010075
The inequality is 7x + 21 
Step-by-step explanation:
<u>DATA:</u>
Let the number be x
Number times 7 = 7*x
Sum of a number times 7 and 21 = 7x + 21
Is at least 29
<u>INEQUALITY:</u>
7x + 21 
<u>SOLVE:</u>
7x
7x
x 
Therefore, the inequality is 7x + 21 
Keyword: Inequality
Learn more about inequality at
#LearnwithBrainly
The number is -45 (negative 45)