The given operation involves just swapping the two rows, so carrying out

on the matrix gives
X = large boxes and y = small boxes
x + y = 70.....x = 70 - y
60x + 65y = 4300
60(70 - y) + 65y = 4300
4200 - 60y + 65y = 4300
5y = 4300 - 4200
5y = 100
y = 100/5
y = 20 <=== the small boxes weigh 20 lbs
x + y = 70
x + 20 = 70
x = 70 - 20
x = 50 <== and the large boxes weigh 50 lbs
It might be nineteen because nineteen minus seven is twelve. twelve minus two is ten.
The answer is (rounded to the nearest tenth) about 5.7 and since neither 18 or 2 have a perfect square, so this is irrational.
Answer:
Step-by-step explanation:
Area of the good part= area of whole roof - area of bad part
Since the roof is a square roof, the area will be calculated using the formulae for area of a square
Area of a square =length²
Area of good part =(x+12)²-x²
A= {(x+12)(x+12)} - x²
A = (x²+12x+12x+144) -x²
Open the bracket and rearrange the equation
A= x²-x²+24x+144
A=(24x+144) ft