How would I solve this system of equations with SUBSTITUTION? Please explain step by step!!BRAINLIEST, THANKS, AND 5-STAR REVIEW TO BEST ANSWER!

Pls urgent max amount of points will be given and pls do not answer if unsure or you will be reported by me and brainliest answer gets the brainliest .. thing so yeh

In the figure below, segment ac is congruent to segment ab: triangle abc with a segment joining vertex a to point d on side bc. side ab is congruent to side ac which statement is used to prove that angle abd is congruent to angle acd? segment ad bisects angle cab. triangle acd is similar to triangle abd. segment ad is congruent to segment ac. angle cab is congruent to angle cba.

D(5, 7). e(4,3), and f(8, 2) form the vertices of a triangle. what is mzdef? oa. 30° ob. 45° oc. 60° od 90°