Lines l and m are parallel. If m∠3 = 3x + 11 degrees and m∠2 = 4x + 1 degrees, what is the measure of ∠7? 41 degrees 139 degrees 180 degrees

m<7 = 139°

Step-by-step explanation:

Given:

m<3 = (3x + 11)°

m<2 = (4x + 1)°

Required:

m<7 = ?

SOLUTION:

Given that l and m are parallel lines, m<3 and m<2 are alternate interior angles.

Alternate interior angles are congruent. Therefore:

m<3 = m<2

(substitution)

Solve for x

Divide both sides by -1

Find m<2:

m<2 = (4x + 1)

Plug in the value of x

m<2 = 4(10) + 1 = 40 + 1

m<2 = 41°

Find m<7:

m<2 + m<7 = 180° (consecutive interior angles are supplementary)

41° + m<7 = 180° (substitution)

m<7 = 180 - 41 (subtracting 41 from each side)

m<7 = 139°

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3