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: Combine like terms: Apply the subtraction property of equality: Apply the division property of equality:

X = 1

Step-by-step explanation:

To solve the system of equation by susbtitution:

3x + y = 9

y = –4x + 10

We can follow the steps thus:

Substitute the value of y in the first equation:

As in the second equation y = -4x + 10 we can substitute in the first equation as follows:

3x + y = 9

3x + -4x + 10 = 9

Combine like terms:

3x + -4x + 10 = 9

Like therms are the therms with X (3x - 4x = -1x):

-1x + 10 = 9

Apply the subtraction property of equality:

-1x + 10 = 9

As 10 is suming, it passes to subtracting the 9:

-1x  = 9 - 10

-1x = -1

Apply the division property of equality:

-1x = -1

Dividing in -1:

x = -1 / -1

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)