The value of x in this system of equations is 1
3x + y = 9
y = 4x + 10
substitute the value of y in the first equation:
2. combine like terms
-3. apply the subtraction property of equality
4. apply the division property of equality
3x + (-4x + 10) = 9
-x + 10 = 9
1
what is the value of y?
y=

x=-1/7, y=66/7. (-1/7, 66/7).

Step-by-step explanation:

3x+y=9

y=4x+10

3x+4x+10=9

7x+10=9

7x=9-10

7x=-1

x=-1/7

y=4(-1/7)+10

y=-4/7+10

y=-4/7+70/7

y=66/7

First write the equations in the slope-intercept form:


Line 1 passes through the points (-6,-6) and (-4,-3).


Line 2 passes through the points (0,3) and (2,6).


These are two identical lines so the system of equations has infinitely many solutions. The answer is D.