Find the output, y, when the input, x, is -9

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality

The distance from the sun to earth is about 1.5×10 to the 11th m suppose light travels at a speed of 3×10 to the 8th m per second about how long does it take light from sun to reach earth

Me with these questions , i don’t understand scientific notation!