Question

The sum of two numbers, a and b, is 8.25. The difference between the two numbers is 0.75. Which equation can be used to determine the value of a? Options: 2a = -9, 2a = 7.5, 2a = -7.5, 2a = 9.

Answer 1

To determine the value of a when the sum of two numbers is 8.25 and the difference is 0.75, we can set up the equation 2a = 9.

Step-by-step explanation:

The sum of two numbers, a and b, is 8.25. The difference between the two numbers is 0.75. To determine the value of a, we can set up the equation:

a + b = 8.25

Since the difference between the two numbers is 0.75, we can also set up the equation:

a - b = 0.75

To solve these equations, we can use the method of substitution or elimination. Let's use the method of substitution:

From the first equation, we can solve for b:

b = 8.25 - a

Now, substitute this value of b into the second equation:

a - (8.25 - a) = 0.75

Simplify the equation:

2a - 8.25 = 0.75

Add 8.25 to both sides:

2a = 9

Divide both sides by 2:

a = 4.5

So, the correct equation to determine the value of a is: 2a = 9.