Answer:
D
Step-by-step explanation:
Answer:
(3,-4) or x=3 and y= -4
Step-by-step explanation:
I'm going to solve this by substitution
We first need to get a variable by itself in one of the two equations (it doesn't matter which variable and the equation you do the work on doesn't matter either)
I'm going to solve for y in the second equation
-4x-4y=4
add 4y and subtract 4 from both sides to get
-4x-4=4y
Divide by 4 to get
-x-1=y
We can plug this value in for y into the first equation and get
4x+5(-x-1)= -8
Solve for x
4x-5x-5= -8
-x-5= -8
-x= -3
x=3
We can plug this value into one of the first two equations and solve for y
4(3)+5y= -8
12+5y= -8
5y= -20
y= -4
Therefore the solution is (3,-4) or x=3 and y= -4
Answer:
24: x = 31
25: x = 15
Step-by-step explanation:
Remark
24 is supplementary which means that the two angles add to 180o which is on the right hand side of the equation
25 is complementary which means that the two angles add to 90o which is on the left hand side of the equation
Twenty Four
3x + 31 +2x - 6 = 180 Collect the like terms
3x +2x + 31 - 6 = 180 Do the adding and subtracting.
5x + 25 = 180 Subtract 25 from both sides
5x + 25 - 25 = 180 - 25
5x = 155 Divide by 5
x = 155/5
x = 31
Check
3x + 31 = 3*31 + 31
3x + 31 = 93 + 31
3x + 31 = 124
2x - 6 = 2*31 - 6 = 62 - 6 = 56
Total 124 + 56 = 180 as it should.
Twenty Five
Equation
3x+ 4x - 15 = 90
Solution
7x - 15 = 90 Like terms have been collected on the left.
7x = 90 + 15 15 was added to both sides
7x = 105 Divide by 7
x = 15 I'll leave the check to you
Answer:
n = 80 / 10, or 8.
Step-by-step explanation:
Everything is on the picture.
