Complete the two-column proof.
Given: measure angle upper R upper S upper T equals 5 x degrees and measure angle upper U upper V upper W equals 7 x degrees
angle upper R upper S upper T and angle upper U upper V upper Ware supplementary
Prove: x =15
Statements Reasons
1. angle RST + angle UVW = 180° Given: Supplementary angles
2. 5x + 7x = 180° Substitution (Substitute the given angle measures)
3. 12x = 180° Combine like terms
4. x = 180°/12 Divide both sides by 12
5. x = 15° Simplify