An equvilent equation
remember you can do anything to an equation as long asyou do it to both sides
assuming yo have
x+y=1 and
x-3y=9
mulitply both by 2
2x+2y=2
2x-6y=18
those are equvilent
ok, solve initial
x+y=1
x-3y=9
multiply first equation by -1 and add to 2nd equation
-x-y=-1
<u>x-3y=9 +</u>
0x-4y=8
-4y=8
divide both sides by -4
y=-2
sub back
x+y=1
x-2=1
add 2
x=3
x=3
y=-2
(3,-2)
if we test it in other one
2x+2y=2
2(3)+2(-2)=2
6-4=2
2=2
yep
2x-6y=18
2(3)-6(-2)=18
6+12=18
18=18
yep
solution is (3,-2)
Answer: 1/8 is left over.
Step-by-step explanation:
Tess already at half of the pizza, and Shawn ate a quarter of the pizza.
1/2 + 1/4= 3/4
There is a quarter of pizza remaining, but Molly ate half of that quarter (1/8). There is only 1/8 of pizza left.
Answer:
59.4 km
Step-by-step explanation:
First you need to find the circumference of the circle. 20*3.14=62.8. Then, you divide this by two, because there is only half of a circle, to get 31.4.
Then you can just add 16 + 12 + 31.4 to get 59.4.
mathematically the answer to that is 18 because 10.2 minus 2.4 is equal to the difference of 7.8 and 7.8 plus 10.2 is equal to the sum of exactly and positively 18
