Answer:
a) Add 4 to both sides, and then divide by 2. The solution is 
.
Step-by-step explanation:
Question:
Which of the following describes the correct process for solving the equation 2x − 4 = 20 and arrives at the correct solution?
a) Add 4 to both sides, and then divide by 2. The solution is x = 12.
b) Divide both sides by −4, and then subtract 2. The solution is x = −7.
c) Subtract 4 from both sides, and then divide by 2. The solution is x = −12.
d) Multiply both sides by −4, and then divide by 2. The solution is x = −40.
Solution:
Given equation:
We need to determine the steps in order to solve for 
.
Solving for .
Step 1: Adding 4 both sides.
Step 2: Dividing both sides by 2.
∴
Thus, we added 4 both sides and then divided both sides by 2 to get solution = 12
Answer:
Morning's average rate = 50 mph, and Afternoon's average rate = 25 mph.
Step-by-step explanation:
Suppose he drove 150 miles for X hours, then his average rate in the morning was (150/X) mph.
Given that he spent 5 hours in driving.
And he drove 50 miles for (5-X) hours, then his average rate in the afternoon was 50/(5-X) mph.
Given that his average rate in the morning was twice his average rate in the afternoon.
(150/x) = 2 * 50/(5-x)
150/x = 100/(5-x)
Cross multiplying terms, we get:-
150*(5-x) = 100*x
750 - 150x = 100x
750 = 100x + 150x
750 = 250x
x = 750/250 = 3.
It means he spent 3 hours in the morning and 2 hours in the afternoon.
So morning's average rate = 150/3 = 50 mph.
and afternoon's average rate = 50/(5-3) = 25 mph.
Answer:
Increase by $145
Step-by-step explanation:
= $ (x + 145 + 145)
= $ (x + 290)
Answer:x = -9, y = -7
Step-by-step explanation:
Equation 1) -x + 4y = -19
Equation 2) -3x + 3y = 6
Multiply ALL of equation 1 by 3 so that both equations include -3x in it.
1) 3(-x + 4y = -19)
Simplify.-3x + 12y = -57 → equation 3
Now, subtract equation 3 from equation 2.
-3x + 12y = -57
(-)-3x + 3y = 6
Simplify.
9y = -63
Divide both sides by 9.
9y ÷ 9 = -63 ÷ 9
Simplify.
y = -7
Now that we have the value for y, simply plug in -7 for y into equation 1.
1) -x + 4y = -19-x + 4(-7) = -19
Simplify.-x - 28 = -19
Add 28 to both sides of the equal sign.
-x - 28 + 28 = -19 + 28
Simplify.-x = 9
Divide both sides by -1.x = -9
Now we know that : x = -9, y = -7
To check our work, simply plug in -9 for x and -7 for y into equation 1.
1) -x + 4y = -19-(-9) + 4(-7) = -19
Simplify.
9 - 28 = -19-19 = -19
Therefore, x = -9, y = -7
Hope this helped! :)
