Mental math
Mental math
350*2
350*2=700
What does the absolute value mean?
A number’s distance from zero.
2x - 8 = -x + 4
x=4
What is the reciprocal of 3/4
4/3
convert 120% to a decimal
1.2
Mental math
25*5=
25*5=125
What is a acute angle?
An angle whose measure is greater than 0 and less than 90 degrees.
-x = 6
-x = 6 : given
x = -6 : multiply both sides of the equation by -1
Which of these numbers is divisible by 3?
A) 156312
B) 176314
A) 156312 , is divisible by 3
convert 4 8/5 to a decimal
5.6
Mental math
264*45=
264*45=11880
What is the domain?
The set of input values in a function.
2x + 1/2 = 2/3
2x + 1/2 = 2/3 : given
2x + 1/2 - 1/2 = 2/3 - 1/2 : subtract 1/2 from both sides
2x = 1/6 : group like terms
x = 1/12 : multiply both sides by 1/2
Evaluate the following exponential expressions.
A) -42
B) (-2)3
A) - 42 = - (4 × 4) = -16 : expand and calculate
B) (-2)3 = (-2)×(-2)×(-2) = -8 : expand and calculate
convert 3/10 to a percent
30%
Mental math
453*3=
453*3=1359
What is the origin?
he point with coordinate 0 on a number line; the point with coordinates (0, 0) in the coordinate plane.
x/3 + 2 = 5
x/3 + 2 = 5 : given
x/3 + 2 - 2 = 5 - 2 : subtract 2 from both sides
x/3 = 3 : group like terms
x = 9 : multiply both sides by 1/2
Simplify the following algebraic expressions.
A) -2x + 5 + 10x - 9
B) 3(x + 7) + 2(-x + 4) + 5x
A) -2x + 5 + 10x - 9 : given
= (10x - 2x) + (5 - 9) : put like terms together
= 8x - 4 : group
B) 3(x + 7) + 2(-x + 4) + 5x : given
= 3x + 21 - 2x + 8 + 5x : expand
= (3x - 2x + 5x) + (21 + 8) : put like terms together
= 6x + 29 : group
convert 1.4 to a percent
140%
Mental math
45000*4=
45000*4=180,000
What does perpendicular mean?
Lines are perpendicular if they intersect to form a right angle. Segments are perpendicular if the lines containing the segments are perpendicular.
-5/x = 2
-5/x = 2 : given
-5 = 2x : multiply both sides by x and simplify
-5/2 = x : : multiply both sides by 1/2
Simplify the expressions.
A) (2x - 6) / 2
B) (-x - 2) / (x + 2)
C) (5x - 5)/10
A) (2x - 6) / 2 : given
= 2(x - 3) / 2 : factor 2 in numerator
= x - 3 : divide numerator and denominator by 2 to simplify
B) (-x - 2) / (x + 2) : given
= -1(x + 2) / (x + 2) : factor -1 in numerator
= -1 : divide numerator and denominator by x + 2 to simplify
C) (5x - 5)/10 : given
= 5(x - 1) / 10 : factor 5 in numerator
= (x - 1) / 2 : divide numerator and denominator by 5 to simplify
convert 123.45 to a percent
12345%