Answer:
X is 160. because you can add all the value of x. But first substrate 540 with 100 which is 440. then 1/2x + 1/2x+ (x-15) + (x-25) which is further simplified as x + 2x - 40. then it's further simplified as 3x - 40 = 440. then add 40 with 440 which is 480 then divide it by 3 which is 160. therefore X= 160.
Divide 8.5 by .3 and get 28.3333. She can't make tacos with the extra .3 pounds so the answer is 28 tacos
Let us assume the number to be = x
Then
(80/100) * x = 56
4x/5 = 56
4x = 56 * 5
4x = 280
x = 280/4
= 70
The value of the unknown number is 70. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems in future without requiring any help from outside. Only thing that needs to be taken care of is the calculation part.
The formula of a slope:

We have the points (-4, -3) and (-3, s) and the slope m = 3. Substitute: