Final answer:
To solve the equation t+7=12, subtract 7 from both sides to find t. Then substitute t into t+7=4-x, and solve for x by isolating the variable.
Step-by-step explanation:
To solve the equation t+7=12, we need to isolate the variable t. We can do this by subtracting 7 from both sides of the equation:
t + 7 - 7 = 12 - 7
t = 5
Now, we can substitute the value of t into the equation t+7=4-x:
(5) + 7 = 4 - x
12 = 4 - x
To solve for x, we need to isolate the variable by subtracting 4 from both sides:
(12) - 4 = (4 - x) - 4
8 = -x
To get the value of x, we multiply both sides of the equation by -1:
8 * -1 = -x * -1
x = -8