69:
I know for a fact it can't be (B).
The answer is (A).
Reason: 6 times 9 is 54.
70:
13 is change to 15
13 plus 2 is 15
17 plus 2 is 19
I am 100% sure for question 69, but for question 70 im 100% unsure.
Answer:
It was difficult reading the question, as written. Check my assumptions.
Step-by-step explanation:
"five more than the product of two and a number,
decreased by seven"
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Let the "number" be a.
We are told "five more than . ." means +5,
"the product of two and a number" means 2a,
"decreased by seven" mean -7
Put the statements together to obtain:
+5+2a-7
Simplify to 2a-2
Evaluate when a = 8:
2a-2
2(8)-2
16-2
= 14
The perimeter of a rectangle is given by the formula,
We substitute,
and
into the above formula to obtain the expression,
We now group the x and y terms on the Left Hand Side of the equation to get.
We now divide through by 2 to get,
Therefore the width of the rectangle is
The top row of matrix A (1, 2, 1) is multiplied with the first column of matrix B (1,0,-1) and the result is 1x1 + 2x0 + 1x -1 = 0 this is row 1 column 1 of the resultant matrix
The top row of matrix A (1,2,1) is multiplied with the second column of matrix B (-1, -1, 1) and the result is 1 x-1 + 2 x -1 + 1 x 1 = -2 , this is row 1 column 2 of the resultant matrix
Repeat with the second row of matrix A (-1,-1.-2) x (1,0,-1) = 1 this is row 2 column 1 of the resultant matrix, multiply the second row of A (-1,-1,-2) x (-1,-1,1) = 0, this is row 2 column 2 of the resultant
Repeat with the third row of matrix A( -1,1,-2) x (1,0, -1) = 1, this is row 3 column 1 of the resultant
the third row of A (-1,1,-2) x( -1,-1,1) = -2, this is row 3 column 2 of the resultant matrix
Matrix AB ( 0,-2/1,0/1,-2)
