Find the 53rd term of the arithmetic sequence –12, -1, 10, ...

560

Step-by-step explanation:

you listed the first 3, so it's 53 - 3 = 50 and you multiply 50 and 11 (the sequence is +11) to get 550. Add 10 and you get 560!

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.