643=4 x 160+n in 5 grade math

We need to solve the equation

The first thing we are going to do is perform the multiplication :

Remember that the most important thing to solve and equation is isolate (left the variable alone) in one side of the equation. Notice that we can isolate the variable, , in our equation by subtracting 640 from both sides of the equation:

Now, let's check if the solution is a valid solution for our equation; to do it, we are going to replace with in our original equation and check if the resulting equation is true:

Look! our equation is true; we can conclude that is the solution of the equation .

(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