Solve by elimination.
The goal is to cancel out one of the variables in order to easily solve for the other variable.
Do this by changing the equations so that the coefficients of either x or y add up to 0.
Notice the coefficients of y are 3 and 3, if we make one of them negative then they add up to 0. 3+ (-3) = 0
Multiply 2nd equation by -1.
6x +3y = 9
-2x -3y = -1
__________
4x +0y = 8
Solve for x
4x = 8
x = 8/4 = 2
Plug x=2 back into one of original equations to find y.
---> 2(2) + 3y = 1
---> 4 + 3y = 1
---> 3y = -3
---> y = -1
Therefore solution is (2,-1)
Answer:
34 feet
Step-by-step explanation:
From the question, we are told that:
If the room is 30 feet high at the center and 90 feet wide at the floor,
Entire width of the room = 90 feet = 2a
a = 90/2 = 45
Height of the room = b = 30 feet
Foci (c)² = a² - b²
c = √a² - b²
c = √45² - 30²
c = √1125
c = 33.541019662 feet
Approximately to the nearest whole number = 34 feet
Denise and Donna should each stand 34 ft from the outer wall so that they will be positioned at the foci of the ellipse
Answer:
Yvette cleared 10 large driveways
Step-by-step explanation:
small driveway = x
big driveway = y
x+y = 25
15x + 25y = 475
y = 25-x
15x + 25(25-x) = 475
-10x + 625 = 475
10x = 150
x= 15
15 + y = 25
y =10
10 large driveways, 1 5 small driveways
Answer:
4 - ( 3x - 8 ) = 21
break the bracket first ,it gives : 4 - 3x + 8 = 21
12 - 3x = 21
- 3x = 21 - 12
- 3x = 9
-x = 9/3
-x = 3
X = - 3
[ check if the answer is correct, put -3 instead of X in the above equation ! we get 4 - { 3(-3) - 8 } = 21
4 - { - 9 - 8 } = 21
4 - { - 17 } = 21
break the bracket, minus and minus will multiply and will become plus , so we have 4 + 17 = 21 , hence 21 = 21 ! therefore X = -3
Answer:
f(x) = x*3/4 + 42.5
Step-by-step explanation:
The original difference between the pair is 70 - 30 = 40
The new difference between the pair is 95 - 65 = 30
Since the differences are not the same, Mrs Bailey must first perform a (slope) multiplication by a factor of 30/40 or 3/4
Then 30 * 3/4 = 22.5
Then she can shift the scores up by 65 - 22.5 = 42.5 in order to get the range from 65 to 95
Therefore, f(x) = x*3/4 + 42.5. We can test that
f(30) = 30*3/4 + 42.5 = 65
f(70) = 70*3/4 + 42.5 = 95
