Set up an equation and solve to find the unknown in the following cases.a) When I subtracted 11 from twice a number, the result was 15

To solve this problem, we need to set up an equation based on the given information. Let's call the unknown number "x".

According to the problem, when we subtract 11 from twice the number, the result is 15. Mathematically, this can be written as:

2x - 11 = 15

To find the value of x, we need to isolate it on one side of the equation. Let's solve for x step by step:

1. Add 11 to both sides of the equation: 2x - 11 + 11 = 15 + 11 2x = 26

2. Divide both sides of the equation by 2 to solve for x: (2x)/2 = 26/2 x = 13

Therefore, the unknown number is 13.