183k views
1 vote
Help with my math please

Help with my math please-example-1
User Bobbo
by
8.1k points

1 Answer

2 votes

Answer:

Explanation:

x+y=5; x-y=3Adding both equations, we get:

2x = 8

x = 4Substituting the value of x in any of the equations:

x+y=5

4+y=5

y=1So the solution to this system of equations is: x=4, y=1.3x+y=11; y=x+3Substituting y=x+3 in the first equation:

3x+x+3=11

4x=8

x=2Substituting x=2 in the second equation:

y=x+3

y=2+3

y=5So the solution to this system of equations is: x=2, y=5.x+3y=0; 2x-y=-7Multiplying the second equation by 3 to eliminate y:

6x-3y=-21Adding both equations, we get:

7x=-21

x=-3Substituting x=-3 in the first equation:

x+3y=0

-3+3y=0

y=1So the solution to this system of equations is: x=-3, y=1.y=-3x-2; 6x+2y=-4Substituting y=-3x-2 in the second equation:

6x+2(-3x-2)=-4

6x-6x-4=-4

-4=-4This means that the two equations are equivalent and represent the same line. Therefore, there are infinitely many solutions to this system of equations.-4x+5y=27; x-6y=-2Multiplying the second equation by 5 to eliminate y:

5x-30y=-10Adding both equations, we get:

x-4x+5y-30y=-2+27

-x-25y=25

25y=-x-25

y=-(1/25)x-1Substituting y=-(1/25)x-1 in the first equation:

-4x+5(-(1/25)x-1)=27

-4x-5/5x-5=27

-9x=32

x=-32/9Substituting x=-32/9 in the expression for y:

y=-(1/25)(-32/9)-1

y=83/225So the solution to this system of equations is: x=-32/9, y=83/225.

User Oscar Peli
by
8.3k points

No related questions found