4. Evaluate -8÷2+12×9-4x6\
56÷7x2

98

Step-by-step explanation:

In Questions that involve multiple mathematical operations, we use the BODMAS or PEMDAS.

BODMAS is an acronym and it represents; Bracket, Order, Division, Multiplication, Addition, and Subtraction.

PEMDAS is also an acronym that means the same thing with BODMAS, it represents; Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction

We solve using the order present in BODMAS

-8 ÷ 2 + 12 × 9 - 4 x 6 \  56 ÷ 7 x 2

Solving all Multiplication, we have;

-8 ÷ 2 + 12 × 9 - 4 x 6 \  56 ÷ 7 x 2

-8 ÷ 2 + 108 - 24 \  56 ÷ 14

Solving all Division, we have;

-8 ÷ 2 + 108 - 24 \  56 ÷ 14

-4 + 108 - 24 \  4

-4 + 108 - 6

Solving all Addition, we have;

-4 + 108 - 6

104 - 6 = 98

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

i think it would be 42cm