Answer:
The sum of the internal ángles = 360°
(3y+40)° and (3x-70°) are suplementary angles = 180°
then:
(3x-70) + (3y+40) + 120 + x = 360 ⇒ first eq.
(3y+40) + (3x-70) = 180 ⇒ second eq
development:
from the first eq.
3x + x + 3y = 360 + 70 - 40 - 120
4x + 3y = 430 - 160
4x + 3y = 270 ⇒ third eq.
3y = 270 - 4x
y = (270 - 4x) / 3 ⇒ fourth eq.
from the secon eq.:
3y + 3x = 180 + 70 - 40
3y + 3x = 250 - 40
3y + 3x = 210 ⇒ fifth eq.
multiply by -1 the fifth eq and sum with the third eq.
-3y - 3x = -210 ⇒ (fifth eq. *-1)
3y + 4x = 270
⇒ 0 + x = 60
x = 60°
from the fourth eq.
y = (270-4x)/3
y = (270-(4*60)) / 3
y = (270 - 240) / 3
y = 30/3
y = 10°
Probe:
from the first eq.
(3x-70) + (3y+40) + 120 + x = 360
3*60 - 70 + 3*10 + 40 + 120 + 60 = 360
180 - 70 + 30 + 40 + 120 + 60 = 360
180 + 30 + 40 + 120 + 60 - 70 = 360
430 - 70 = 360
Answer:
y = 10
Step-by-step explanation:
2x + 2y = 3 ( x2 for everything in the equation)
x - 4y = -1
4x+ 4y = 6
x - 4y = -1
Add the 1st line to the 2nd line to get rid of the y:
5x = 5
x - 4y = -1 ( you can pick any line from this system to be the second equation in this step, you can put 2x + 2y = 3 or 4x+ 4y = 6, anything above this step, but to make it simple chose the one you think is the easiest)
Solve for x, then plug the x value into the 2nd equation
x = 1
1 - 4y = -1
x = 1
-4y = -2 =) y = 1/2
x = 1
y= 1/2
Answer:
(0,-1)
Step-by-step explanation:
(0,-1) will work because when you plug them is it is equivalent to 4
Answer:1100
Explanation:89% of 10,000 is 8900 subtract 8900 from 10,000 bam you got 1100
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