In order to solve this question we need to represent "y "in terms of "x" in the first equation, and the plug in the "y" value in the first equation into the second one. Luckily for us in the first equation it already shows what "y" is equal to in terms of "x" (based on the first equation y = -x + 10). Now we just need to plug in the value that we got instead of "y" in the second equation, and so we get....
y = 7x + 2
(plug in the y value and get the following ….)
-x + 10 = 7x + 2
(now just solve the following equation)
-x + 10 + x = 7x + 2 + x
10 = 8x + 2
10 - 2 = 8x + 2 - 2
8 = 8x
8/8 = 8x/8
1 = x
Now that we know the value of "x", all we need to do now is substitute the value of "x" into any of the equations and we will get the value of "y". So we do the following.....
Learn how to find the distance between two points by using the distance formula, which is an application of the Pythagorean theorem. We can rewrite the Pythagorean theorem as d=√((x_2-x_1)²+(y_2-y_1)²) to find the distance between any two points. Created by Sal Khan and CK-12 Foundation.
Answer: It decreased by 24F not 10F because if it were 10F the starting temperature had to be -7F since the difference between this number and -17F is 10F but in this case it starts at 7F so we subtract 7-0=7 and 17-0=17 and add 17+7=24F.