Answer: a
Step-by-step explanation:
First question:
1. Set equations equal to each other so 5x-9=2x+6
2. Put x's on one side so that 3x=15
3. Divide by 3 so that x=15
4. Substitute 15 in for x so that y=2(15)+6
5. Solve for y so that y=36
6. Thus the equations intersect at (15,36)
Second question:
1. Since for lines y=mx+b, and m=slope=3 you only need to write an equation with slope 3
2. y=3x+b, b can be any number
If you were to make both x's equivalent, you'd have to multiply the first equation by 2 to get rid of the coefficient, 1/2. However, you'd have to multiply 2 onto -8 as well, therefore the equation would turn into x - 16 = 18. That is not equivalent to x - 8 = 18.