∠a and \angle b∠b are vertical angles. if m\angle a=(4x+23)^{\circ}∠a=(4x+23) ∘ and m\angle b=(5x-7)^{\circ}∠b=(5x−7) ∘ , then find the measure of \angle b∠b.

12 3 4 5 6 7 8 9 10 time remaining 59: 02 charlie is evaluating the product of 0.09 and 0.05. he multiplies, and before placing the decimal, arrives at an answer of 45. after considering the decimal placement, what is charlie's final answer? 0.0045 0.045 0.45 0.4545 mark this and return