Answer please please I cant think

∠A = 20°; ∠B = 59°; ∠C = 101°

Step-by-step explanation:

According to the problem:

All interior angles within a triangle adds up to 180°:

∠A + ∠B + ∠C = 180°

Substitute in the value of ∠A into the other equations:

∠B = 4 · ∠A - 21° = 4(20°) - 21° = 80° - 21° = 59°

∠C = 5 · ∠A + 1° = 5(20°) + 1° = 100° + 1° = 101°

1.30

step-by-step explanation:

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -