Answer:
x=7
z=79
Step-by-step explanation:
13x+10=101
13x=91
x=7
180-101=79
Well hmmm let's say you take the car and go in the city for 60 miles with it, well, the car can do 60 miles per gallon, since you just drove it for 60 miles, you only spent 1 gallon of gasoline then.
that only happens if you drive it for 60 miles, what if you drive it for more, let's do a quick table on that,

and so on, now let's check if you less than 60 miles,

so, if you divide the amount of miles driven, by 60, when you have driven it for 120 miles, 120/60 is just 2, and the cost is for 2 gallons, or 3.6 * 2, which is 7.2 bucks, for 180 miles is 180/60 or 3 gallons for 3.6 * 3 bucks, and so on.
now, what if you drive it instead for "m" miles?
Answer:
division by whatever each is worth, hope this makes sense!
Step-by-step explanation:
Treat the matrices on the right side of each equation like you would a constant.
Let 2<em>X</em> + <em>Y</em> = <em>A</em> and 3<em>X</em> - 4<em>Y</em> = <em>B</em>.
Then you can eliminate <em>Y</em> by taking the sum
4<em>A</em> + <em>B</em> = 4 (2<em>X</em> + <em>Y</em>) + (3<em>X</em> - 4<em>Y</em>) = 11<em>X</em>
==> <em>X</em> = (4<em>A</em> + <em>B</em>)/11
Similarly, you can eliminate <em>X</em> by using
-3<em>A</em> + 2<em>B</em> = -3 (2<em>X</em> + <em>Y</em>) + 2 (3<em>X</em> - 4<em>Y</em>) = -11<em>Y</em>
==> <em>Y</em> = (3<em>A</em> - 2<em>B</em>)/11
It follows that

Similarly, you would find

You can solve the second system in the same fashion. You would end up with

Answer:
<h2>181 440</h2>
Step-by-step explanation:
We have 9 choices for Choosing the first object
8 choices for Choosing the 2nd object
.
.
.
3 choices for Choosing the seventh object
Therefore if we want to choose7 objects without replacement from 9 objects we have : 9×8×7×6×5×4×3 = 181 440
Also ,we can calculate it this way :
9P7 = 181 440