Answer:
The right options are A and D.
Step-by-step explanation:
1. Option A.
The action is:Add 3 to both sides. This means that we need to do the following operation:
x - 3 = 12
∴ x - 3 + 3 = 12 + 3
∴ x = 15
So, the solution of this problem is x = 15.
2. Option D.
The property is:Addition property of equality. This is the property we are chosen because we need to isolate the variable x. To do that, we need to add a number of each side of the equation to find our goal and this property allows us to get our goal.
B. First and Second St appear to be parallel
The average of any two numbers lies between those two numbers:
To take a percent, move the decimal point of the percent two places to the left. 7% = 0.07
Then multiply:
12.60 • 0.07 = 0.88
12.60 + 0.88 = 13.48
The total cost is: $13.48
In this case, since one equation is in the form of x=, substitution would be best for this problem. Simply plug in 4y + 8 in place of x in the second equation, solve for y, then plug that value into the first equation to find x.
