1 )
1st and 2nd equation (multiply 1st by -2 ):
-2x - 10 y + 8 z = 20
2 x - y + 5 z = -9
---------------------------
- 11 y + 13 z = 11 / * ( -20 )
1st and 3rd:
- 2 x - 10 y + 8 z = 20
2 x - 10 y - 5 z = 0
-----------------------------
- 20 x + 3 z = 20 / * 11
----------------------------------
220 y - 260 z = -220
- 220 y + 33 z = 220
------------------------------
z = 0, y = -1, x = - 5
2 )
2 x - y + 5 = -4
- 2 x + 3 y - 5 = - 10
Substitution: y = 2 x + 9
- 2 x + 3(2 x + 9 ) = -5
4 x = - 32, x = -8, y = -7, z = 5
3 )
x + y + z = 11
1.5 x+3 y +1.5 z = 21
x = 2 y
------------------------
3 y + z = 11 / * (-2)
6 y + 1.5 z = 21
------------------------
- 6 y - 2 z = -22
6 y + 1.5 z = 21
------------------------
-0.5 z = -1, z = 2, y = 3, z = 6
Answer: the store used 6 pounds of peanuts, 3 pounds of almonds and 2 pounds of raisins.
Answer:
13.5
Step-by-step explanation:
Similar = alike but not the same
A lot of times in geometry it would mean that they have the same shape, just different size, so first find the ratio:
6/12 = 1/2
27 * 1/2 = 27/2 = 13.5
Answer:
Exponents
Step-by-step explanation:
exponents are basic short cut to write numbers like 100, 1000, 10000, 1000000 and so on.
Exponents can also be defined as 10 raised to a power x whether positive or negative

They are mostly used in expressing units in standard form.
<h3>examples of basic positive exponents</h3>




basically the power represent the the number of zeroes after the 1.
<h3>examples of basic negative exponents</h3>




in negative exponents the power represents the number of zeroes before the 1. including the 0 behind the decimal point.
this is the basic lay down of how exponent work but one more quick example for maximum understanding
<h3>quick example</h3>




hope you grasp the concept involved in multiplication with other terms.
cheers
<u>Define x:</u>
Let Fred had x dollar.
Fred = x
Greg = x + 17
<u>Solve x :</u>
x + x + 17 = 85
2x + 17 = 85
2x = 68
x = 34
<u>Find the amount each of them had:</u>
Fred = x = $34
Greg = x + 17 = 34 + 17 = $51
Answer: Greg had $51