X + y = 40.....multiply by -4
4x + 6y = 180
-------------------
-4x - 4y = -160 (result of multiplying by -4)
4x + 6y = 180
------------------add
2y = 20
y = 20/2
y = 10 <===
x = 30
Answer:kara Had $17-$12. Pizza cost =leave u with $5 x.50=10topping
Step-by-step explanation:
Answer:
m<1 = 39°
m<3 = 180-90-39= 51°
Step-by-step explanation:
Lines AC and DB are diagonals and always meet at right angles.
Kites have two sets of equivalent adjacent sides and one set up of congruent opposite angles.
For the first line we have a slope of (y2-y1)/(x2-x1)
(2--2)/(1--1)=4/2=2 so we have:
y=2x+b, now solve for b with either of the points, I'll use: (1,2)
2=2(1)+b
b=0 so the first line is:
y=2x
Now the second line:
(1-10)/(4--2)=-9/6=-3/2 so far then we have:
y=-3x/2+b, using point (4,1) we solve for b...
1=-3(4)/2+b
1=-6+b
b=7 so
y=-3x/2+7 or more neatly...
y=(-3x+14)/2
...
The solution occurs when both the x and y coordinates for each are equal, so we can say y=y, and use our two line equations...
2x=(-3x+14)/2
4x=-3x+14
7x=14
x=2, and using y=2x we see that:
y=2(2)=4, so the solution occurs at the point:
(2,4)
Pick 2 pairs of equations t<span>hen use addition and subtraction to eliminate </span>the same variable<span> from both pairs of equations then it is left with 2 variables
</span>Pick two pairs
<span><span>4x - 3y + z = - 10</span><span>2x + y + 3z = 0
</span></span>eliminate the same variable from each system
<span><span>4x - 3y + z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>4x - 3y + z = - 10</span>
<span>-4x - 2y - 6z = 0</span>
<span>-5y - 5z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>- x + 2y - 5z = 17</span>
<span>2x + y + 3z = 0</span>
<span>-2x + 4y - 10z = 34</span>
<span>5y - 7z = 34
</span></span>Solve the system of the two new equations:
<span><span>-5y - 5z = - 10</span>
<span>5y - 7z = 34</span>
<span>-12z = 24</span>
which is , <span>z = - 2</span>
<span>-5y - 5(- 2) = - 10</span>
<span>-5y = - 20</span>
wich is , <span>y = 4
</span></span>substitute into one of the original equations
<span>- x + 2y - 5z = 17</span>
<span>- x + 2(4) - 5(- 2) = 17</span>
<span>- x + 18 = 17</span>
<span>- x = - 1</span>
<span>x = 1</span>
<span>which is , </span><span>(x, y, z) = (1, 4, - 2)</span><span>
</span>Does 2(1) + 4 + 3(- 2) = 0<span> ? Yes</span><span>
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