Answer:
Yes
Step-by-step explanation:
8 - 15 means subtract the positive number 15 from 8.
8 - 15 = 8 + (-15) = -7
8 - (-15) means subtract the negative number -15 from 8.
Subtracting a negative number is the same as adding a positive number.
8 - (-15) = 8 + 15 = 23
8 - 15 = -7, and 8 - (-15) = 23. The expressions mean different operations and have different answers.
Answer:
C. 35 square centimeters
Step-by-step explanation:
What we need for this question:
The edges of a cube are 5 centimeters each.
The face diagonal is about 7 centimeters. (actually 7.0710678118655 cm)
To find the cross sectional area here, multiply 5 cm by 7 cm.
5 cm * 7 cm
35 cm² is your final answer, so C is the answer.
<h3>Given</h3>
z = 3
2y +z = 1
2x +3y +2z = 13
<h3>Find</h3>
x, y, z
<h3>Solution</h3>
... z = 3 is given
Substitute that into the second equation.
... 2y + 3 = 1
... 2y = -2 . . . . . subtract 3
... y = -1 . . . . . . . divide by the coefficient of y
Substitute these two solutions into the third equation.
... 2x +3(-1) +2(3) = 13
... 2x = 10 . . . . . . . . . . . . collect terms, subtract 3
... x = 5 . . . . . . . . . . . . . . divide by the coefficient of x
The variable values are: x = 5, y = -1, z = 3
