15 (a) Work out
4.36 + 2.89
6.8 - 5.42
Give your answer as a decimal

The answers are as given

4.36 + 2.89 is equal 7.25 and 6.8 - 5.42 is equal 1.38

Step-by-step explanation:

4.36 + 2.89 = 7.25

6.8 - 5.42 = 1.38

7.25

1.38

Step-by-step explanation:

a)  For first addition

4.36 + 2.89

Start adding from the right side. Take the last number and add them together.

9+6 = 15 write 5 and keep 1

Bring forward the kept "1"

3+8 + 1 = 12 write 2 and keep 1

Bring forward the kept "1"

4+2 + 1 = 7write 7

∴ 7.25

b) For second subtraction

6.8 - 5.42 = 1.38

Start from the right side of each number

0 - 2 requires that you borrow "1" from "8" now turning "0" to "10" and "8" to "7".

now, 10 - 2 = 8write 8

         7 - 4 = 3write 3

         6 - 5 = 1write 1

∴ 1.38

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a