The easy answer: If, say, B is the zero matrix, i.e.

then

An estimate helps you place the decimal point because when you place 3.7 and 5.1 to multiply you have to count how many spaces of numbers there are. So the answer is 18.87.
Answer:
n≥-5
Step-by-step explanation:
-3n+2≥-4n-3
add 4n on both sides
n+2≥-3
subtract 2 on both sides
n≥-5
Answer:
WY = 180
Step-by-step explanation:
the diagonals of an isosceles trapezoid are congruent , so
ZX = WY , that is
8y - 4 = 7y + 19 ( subtract 7y from both sides )
y - 4 = 19 ( add 4 to both sides )
y = 23
Then
WY = 7y + 19 = 7(23) + 19 = 161 + 19 = 180