Answer:
x = 5
y = 4
Step-by-step explanation:
1. 2x + 2y = 18
2. x + 3y = 17
Multiply the first equation by 1 and the second equation by 2 to eliminate x
We have
2x + 2y = 18
2x + 6y = 34
Subtract equation 2 from equation 1
-4y = -16
Divide both sides by -4 to isolate y
-4y/-4 = -16/-4
y = 4
Now substitute 4 for y in either equation to get x. Using equation 2 we have
x + 3y = 17
x + 3 x 4 = 17
x + 12 = 17
Subtract 12 from both sides
x + 12 - 12 = 17 - 12
x = 5
x = 5 and
y = 4
X= # students who got lower grades
2x+3= # students with grade A
STEP 1:
Add the two sets above equal to 24.
x + (2x + 3)= 24
combine like terms
3x + 3= 24
subtract 3 from both sides
3x= 21
divide both sides by 3
x= 7 (# students lower than A)
STEP 2:
substitute x value from step 1 to find # grade A students
=2x + 3
=2(7) + 3
=14 + 3
=17 (# grade A students)
CHECK:
x + (2x + 3)= 24
7 + 2(7) + 3= 24
7 + 14 + 3= 24
24= 24
ANSWER: There were 17 students with grade A.
Hope this helps! :)
Answer:
the first one
Step-by-step explanation:
Replace x with -2 in the equation and solve.
3(-2) +1 = -6 + 1 = -5
