Algebra
posted by Destiny on .
1,Sovle using the substitution method. Show your work. If the system has no solution or an infinite number of solutions,state this.
x  3y = 20
5x + 3y =40
2 Sovle using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this
3x + 4y = 1
6x + 6y = 3
and
2x + 3y = 37.5
4x + 0y = 24

form the 2nd equation: 3y = 405x
sub into the first:
x  (405x) = 20
x  40 + 5x = 20
4x = 20
x = 5
sub into 3y = 405x
3y = 4025
3y =15y=5
so x=5, y=5
2nd problem:
3x + 4y = 1
6x + 6y = 3
multiply the first by 2 to get
6x  8y = 2
add the 2nd
6x + 6y = 3 to get
2y = 5
y = 5/2
sub into original first
3x + 4(5/2) = 1
3x = 1  10
x = 3
for the last did you notice if you divide the 2nd equation by 4 you get the value of x ?
I will let you finish it.