for what value
of x will the lines 1 and m be
parallel to each other?
Answers
➼ Answer ➼
(i) (3x - 20)° equals to (2x + 10)° as they both are corresponding to each other.
3x - 20 = 2x + 10
⟹ 3x - 2x = 10 + 20
⟹ 1x = 30
⟹ x = 30
Verification:
LHS = (3x - 20)°
= (3 × 30 - 20)°
= (90 - 20)°
= 70°
RHS = (2x + 10)
= (2 × 30 + 10)°
= (60 + 10)°
= 70°
LHS = RHS hence, verified.
Thus the value of both unknown angles equals to 70°
(ii) The sum of (3x + 5)° and 4x° equals to 180° as they are both interior angles on the same side of the transversal and thus are supplementary.
(3x + 5) + 4x = 180
⟹ 3x + 5 + 4x = 180
⟹ 3x + 4x + 5 = 180
⟹ 7x + 5 = 180
⟹ 7x = 180 - 5
⟹ 7x = 175
⟹ x = 175 ÷ 7
⟹ 25
Verification:
LHS = (3x + 5)° + (4x)°
= (3 × 25 + 5)° + (4 × 25)°
= (75 + 5)° + 100°
= 80° + 100°
= 180°
RHS = 180°
LHS = RHS hence, verified.
Thus, (3x + 5)° equals to 80° and 4x° equals to 100°