Question

If 3n + 7 = 25, then find the value of the expression 8n - 3]

In ∆ DEF and ∆ XYZ, DE = XY, angle E = angle Y and EF = YZ. Name the
test of congruency by which both the triangles are congruent.

Answer 1

n=6,

SAS,

63

Explanation:

3n+7=25

3n=25-7

3n=18

n=18/3

n=6

_______________________________

ΔDEF is congruent to ΔXYZ

DE=XY(side)

<E=<Y (angle)

EF=YZ (side)

by SAS congruence criteria ΔDEF=ΔXYZ

_________________________

(Linear pair)

180°-117°

=63

Answer=63