Answer:
m = 1
Step-by-step explanation:
11m + 13 = m + 23
<u>Get m by itself by subtracting m from both sides. </u>
10m + 13 = 23
<u>Subtract 13 from both sides.</u>
10m = 10
<u>DIvide by 10.</u>
m = 1
Mary<span> is 2x = 2*12 = </span>24 years old<span>.</span>
Most of these problems are the commutative property:
Addition
a + b = b + a
Multiplication
a * b = b * a
and the associative property:
Addition
(a + b) + c = a + (b + c)
Multiplication
(a * b) * c = a * (b * c)
There's also the Identity property:
Addition \ Subtraction:
a + 0 = a \ a - 0 = a
Multiplication \ Division:
a * 1 = a \ a / 1 = a
These concepts become more clear when teachers use number disks instead of base ten blocks. Place value is a very important concept for elementary students because base ten is the foundation of our number system.
