Solve this using substitution.
{y=x+1
{2x+y=7

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Before simplifying, how many terms are there in the expression 2x - 5y + 3 + x?

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