System of equations ( substitution methods) can someone solve these problems x=3y-5 ; x+y=3 y=x ; 3x+3y=18 y=3x+4 ; 5x-y=0

(1,2)

(3,3)

(-1/2, 11/2)

Step-by-step explanation:

A system of equations is 2 or more equations for which the same x,y solution exists. We can solve the system in three ways: elimination, substitution, or graphing. Substitution can be used by substituting the value of one variable into the equation.

Pair x=3y-5 and x+y=3

Because x=3y-5, we can substitute 3y-5 into x in x+y=3

x+y=3

(3y-5)+y=3

3y-5+y=3

4y-5=3

4y-5+5=3+5

4y=8

y=2

We now substitute y=2 into x=3y-5.

x=3y-5

x=3(2)-5

x=6-5

x=1

Pair y=x and 3x+3y=18

Because y=x, we can substitute x into y in 3x+3y=18

3x+3y=18

3x+3x=18

6x=18

x=3

We now substitute x=3 into y=x.

y=3.

Pair y=-3x+4 and 5x-y=0

Because y=-3x+4, we can substitute -3x+4 into y in 5x-y=0

5x-y=0

5x-(-3x+4)=0

5x+3x+4=0

8x+4=0

8x=-4

x=-1/2

We now substitute x=-1/2 into y=-3x+4

y=-3x+4

y=-3(-1/2)+4

y=3/2+4

y=11/2

step-by-step explanation:

answer: solve 5\cdot 2^x=2405⋅2  

x

=2405, dot, 2, start superscript, x, end superscript, equals, 240.

solution

to solve for xxx, we must first isolate the exponential part. to do this, divide both sides by 555 as shown below. we do not multiply the 555 and the 222 as this goes against the order of operations!

\begin{aligned} 5\cdot 2^x& =240 2^x& =48 \\ \end{aligned}  

5⋅2  

x

2  

x

​    

=240

=48

​

step-by-step explanation: