PLEASE help me on 3 4 & 5. it’s due before midnight

See below

Step-by-step explanation:

When changing from scientific notation to standard, you want to look at the exponent.

If exponent is positive, move decimal that many times to the right.

If negative, move to the left.

7.875 x 10^4

Exponent is positive so move to the right.

78750

4.53 x 10^-4

Exponent is negative so move to the left.

0.000453

8.9 x 10^-7

Exponent is negative so move to the left

.00000089

jml angle lkj & angle mj = lm