Let

c=54

d=5.5

e=79

f=10

g=1.10 X 10e-2

h = e*g

i = f*g

j = c*(h ± i) = (c*h) ± (c±i)

k = d*(h ± i) = (d*h) ± (d*i)

A = [c*(h ± i)]

B = [d*(h ± i)]

(c±d)*(e±f)*g

=(c±d)*((e*g)±(f*g))

=(c ± d)*(h ± i)

= [c*(h ± i)] ± [d*(h ± i)]

= A ± B

The +/- 5.5 and the +/-10 presumably represent standard deviations. Divide these by 2 (or 1.96) and square to give the variances. Refer to https://stats.stackexchange.com/questions/52646/variance-of-product-of-multiple-random-variables - this gives the result for the variance of a product in terms of the variances of each random variable and its mean (it assumes the random variables are uncorrelated). Take the square root of the variance & multiply by 2 (or 1.96) and this is the error bounds on your product.