Gina willson all about algebra (TRIANGLES ANGLES SUM) HELP ASAP PLEASE

14. Question wise,

In ΔRST,

∠R=2x+5

∠S=x+1

∠T=7x-16

we know,

∠R+∠S+∠T=180 [sum of 3 angles of a triangle is 180°]

2x+5+x+1+7x-16=180

10x-10=180

10(x-1)=180

x-1=18

x=19

so,

∠R=(2×19)+5=43

∠S=19+1=20

∠T=(7×19)-16=117

15. Question wise,

In ΔABC,

∠A=∠C-13

∠B=4∠C-11

we know,

∠A+∠B+∠C=180 [,,]

∠C-13+4∠C-11+∠C=180

6∠C-24=180

6∠C=180+24

∠C=204÷6=34

so,

∠A=34-13=21

∠B=(4×34)-11=125

16. Question wise,

In ΔJKL

∠K=∠J+9

∠L=2∠J-21

we know,

∠J+∠K+∠L=180

∠J+∠J+9+2∠J-21=180

4∠J-12=180

4∠J=180+12

∠J=192÷4=48

so,

∠K=48+9=57

∠L=(2×48)-21=75

first, we define the variables:

x: number of years after 1950

f (x): amount of vinyl sold.

then, with the variables defined, we have:

68594 vinyl records were sold in 1958 > f (8) = 68594

91299 vinyl records were sold in 1961 > f (11) = 91299

38720 vinyl records were sold in 1952 > f (2) = 38720

161743 vinyl records were sold in 1967 > f (17) = 161743

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step-by-step explanation: