Two supplementary angles differ by 40 degrees. Find the larger angle (in degrees).

Class 8Linear Equations in One VariableLinear Equations

Step-by-Step Solution

Supplementary angles sum to 180. Let larger =

x

, smaller =

x - 40. x + (x - 40) = 180

→

2 x - 40 = 180

→

2 x = 220

→

x = 110

degrees.

Answer: C) 110

When

x

appears on both sides, decide which side will keep it (typically the one with the larger coefficient — saves a sign flip). Move the other

x

to that side, sign-flipped.

Example:

5 x - 3 = 2 x + 9

.

- Move

2 x

left:

5 x - 2 x - 3 = 9

→

3 x - 3 = 9

.
- Move −3 right:

3 x = 12

.
- Divide:

x = 4

.

Verify:

5 (4) - 3 = 17

;

2 (4) + 9 = 17

. ✓

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