The third is because the prove is x = fifteen and if a number is next to a letter, it means multiply, sorry I could only do one.
3.49 is the anwser you need
X=-56/3
multiply everything by 4 to cancel the fraction which will give you
3x+20=-36
then combine like terms to get
3x=-56
then divide to get x by itself to get
x=-56/3
since this is a weird decimal, leave it as an improper fraction
In standard form the two equations are
7x +y = 5
7x +y = -5
The equations describe lines that are parallel.
1 is the answer. You put the places in a chart, stem and leaf plot I think its called, look in up up like for another example because it/s been awhile since I learned this
