Question

How do you solve `x+ 4x + 3( 4x ) \leq 680`?

Answer 1

“Simplify” it by performing all of the operations to combine the terms. Then collect all of the constants on one side to calculate the variable/unknown on the other side.

Explanation:

`x + 4*x + 3*(4*x) ≤ 680`
`x + 4*x + 12*x ≤ 680` ; `17*x ≤ 680` ; `x ≤ 680/17` ; `**x ≤ 40**`

CHECK: for x = 20 ; `x + 4*x + 3*(4*x) ≤ 680`
`20 + 4*20 + 3*(4*20) ≤ 680` ; `20 + 80 + 240 ≤ 680` ; `340 ≤ 680` TRUE!

(you can do the same for x = 50 to see that 850 ≤ 680 is NOT True, and that at x = 40 , 680 = 680 is true, and the limit)