-2(7a+ 9b) = –14a + [?]b

-18

Step-by-step explanation:

Left Hand Side = -2(7a + 9b) = -14a - 18b

Comparing it with Right Hand Side, ?  = -18

the unknown, [?], has the value -18.

Step-by-step explanation:

Perform the indicated multiplication on the left side:

-14a - 18b = -14a + [?]b

Adding 14a to both sides, we eliminate a:

-18b = [?]b

Thus, the unknown, [?], has the value -18.

asdfghkl

step-by-step explanation:

asdfghkl

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47