Evaluate and solve for the variable and show your work please. x – 7 = 4 + 10

12 – c = 8

–4 – 10 = 4y + 3y

–42 + 20 = –2x + 13x

x – 7 = 4 + 10 (x=21)

x−7=4+10

x+−7=4+10

x−7=(4+10)(Combine Like Terms)

x−7=14

x−7=14

Step 2: Add 7 to both sides.

x−7+7=14+7

x=21

12−c=8  (c=4)

12+−c=8

−c+12=8

Step 2: Subtract 12 from both sides.

−c+12−12=8−12

−c=−4

Step 3: Divide both sides by -1.

−c

−1

=

−4

−1

c=4

−4−10=4y+3y (y=−2)

−4+−10=4y+3y

(−4+−10)=(4y+3y)(Combine Like Terms)

−14=7y

−14=7y

Step 2: Flip the equation.

7y=−14

Step 3: Divide both sides by 7.

7y

7

=

−14

7

y=−2

-42=20=-2=13x (x=−2

Simplifying

-42 + 20 = 2x + 13x

Combine like terms: -42 + 20 = -22

-22 = 2x + 13x

Combine like terms: 2x + 13x = 15x

-22 = 15x

Solving

-22 = 15x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-15x' to each side of the equation.

-22 + -15x = 15x + -15x

Combine like terms: 15x + -15x = 0

-22 + -15x = 0

Add '22' to each side of the equation.

-22 + 22 + -15x = 0 + 22

Combine like terms: -22 + 22 = 0

0 + -15x = 0 + 22

-15x = 0 + 22

Combine like terms: 0 + 22 = 22

-15x = 22

Divide each side by '-15'.

x = -1.466666667

Simplifying

x = -1.466666667

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°