This can be solved using the addition method in algebra.
two numbers (x and y) that add to 37 and whose difference is 21.
This gives you 2 equations:
x + y = 37
x - y = 21
Add the two together and you'll have one equation with one variable. Solve for that variable and then use that value to help you get the other variable.
If the students current grade is a 90% then we’re of course assuming it’s out of 100% 90/100 Now since the students grade improved 20% from the last grading period then you add that to the previous 100% giving you 90/ 120 = .75 And since grades are in percentages you multiply .75 by 100 giving you 75% as the students previous grade
Comments
Call the 2 numbers are x and y, u have:
x+y=37
x-y=21
----------
x=29
y=8
Hey,
This can be solved using the addition method in algebra.
two numbers (x and y) that add to 37 and whose difference is 21.
This gives you 2 equations:
x + y = 37
x - y = 21
Add the two together and you'll have one equation with one variable. Solve for that variable and then use that value to help you get the other variable.
Make an equation, then solve for x and y.
x+y=37
x-y=21
The y's cancel, and you're left with 2x=58. Divide both sides by 2, and x=29.
Then you would plug in 29 for x to solve for y. 29+y=37 --> 37-29=8.
Hope this helps!
use variables like x and y and set up two equations
x + y = 37
x - y = 21
then write both in terms of y or x
y = 37-x
y = -21 + x
then substitute
37 - x = -21 + x
-2x = -58
x = 29
then plug in x
29 - y = 21
y = 8
so the numbers are 29 and 8
Assign variables to x and y
x+y = 37
x-y = 21
Combine the equations and solve:
2x = 58
x = 58/2 = 29
Now that you have x, plug it back in to one of the equations to get y:
29+y = 37
y = 37-29 = 8
Try those numbers in both equations again to check your work.
29 and 8
take 37 and subtract 21 = 16
take 21 and subtract 16 = 5
you need them to be 21 in difference
21 minus 5 is 16
16 divided by 2 (to add half to the higher number and take half from the lower number) = 8
21 plus 8 = 29
16 minus 8 = 8
29 plus 8 = 37
29 minus 8 = 16
There you go.
If the students current grade is a 90% then we’re of course assuming it’s out of 100% 90/100 Now since the students grade improved 20% from the last grading period then you add that to the previous 100% giving you 90/ 120 = .75 And since grades are in percentages you multiply .75 by 100 giving you 75% as the students previous grade
Set up a system of equations:
x+y=37
X-Y=21
Solve one of the equations for one of the variables:
x=37-y
Plug that into the other equation in place of x:
(37-y)-y=21
Solve for y:
37-2y=21
y=8
Plug this y into one of the equations and solve for x:
X+8=37
X=29
There you go! Hope this helps!
X+Y= 37
X-Y=21
Adding the two equations we get
2X =58
X=29
lets substitute the value of x in the first equation
29+Y=37
Y=37-29
Y=8
(8,29)