13 + 3p = 7 i need finding what p stands for.

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

In the following diagram it is given that dec,ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2

Write the equations in logarithmic form 7^3=343