9514 1404 393
Explanation:
2a+7b=0 . . . . . . . . given [eq1]
3a−5b=31 . . . . . . . .given [eq2]
10a+35b=0 . . . . . . multiplication property of equality 5×[eq1] = [eq3]
21a−35b=217 . . . . .multiplication property of equality 7×[eq2] = [eq4]
31a = 217 . . . . . . . . addition/substitution properties of equality [eq3]+[eq4]
a = 7 . . . . . . . . . . . . division property of equality (÷31)
2(7)+7b=0 . . . . . . . .substitution property of equality; a=7 in [eq1]
14 + 7b = 0 . . . . . . . properties of real numbers
7b=−14 . . . . . . . . . . addition property of equality; add -14
b=−2 . . . . . . . . . . . . division property of equality (÷7)
The sum of the interior angle of a polygon is 720°, thus the value of w will be obtain as follows:
size of each angle is
720/6=120°
thus
8w=120
solving for w we get'
(8w)/8=120/8
w=15°
Answer: w=15°
Answer:
b) y = 3x + 1
y = x+1
Step-by-step explanation:
Select all the systems of equations that have exactly one solution.
a)
y = 3x + 1
y = 3x + 7
y - 3x = 1.... Equation 1
y - 3x = 7...... Equation 2
We solve using Elimination
We Subtract Equation 2 from 1
(y - y ) - (3x - 3x) = 7 - 1
0 = 6
b) y = 3x + 1...... Equation 1
y = x +1...... Equation 2
x = y - 1
We substitute y - 1 for x in Equation 1
y= 3(y - 1) + 1
y = 3y - 3 + 1
y - 3y = -3 + 1
-2y = -2
y = -2/-2
y = 1
Solving for x
x = y - 1
x = 1 - 1
x = 0
x = 0, y = 1,
The Equations in b) have only one solution
c) x+y=10
x = 10 - y
2x+2y=20
We substitute
2(10 - y) + 2y = 20
20 - 2y + 2y= 20
-2y + 2y = 20 - 20
0 = 0
It has no solution
d) x+y=10.... Equation 1
x+y=12..... Equation 2
We solve using Elimination
We Subtract Equation 2 from 1
x - x + y - y = 12 - 10
0 = 2
Answer:
Step-by-step explanation:
:o who is it?!?!?!
Answer:
- 27
Step-by-step explanation:
Hope this helps