Question

the diagram shows a triangle.
what is the value of p?
p = \square^\circ

Explanation:

Step1: Sum angles to 180°

$$55 + (2p+12) + (10p-7) = 180$$

Step2: Simplify left side

$$55+12-7 + 2p+10p = 180$$
$$60 + 12p = 180$$

Step3: Isolate term with $p$

$$12p = 180 - 60$$
$$12p = 120$$

Step4: Solve for $p$

$$p = \frac{120}{12}$$

Answer:

$p = 10^\circ$