An equivalent expression by combining like terms is 12.8 + 6.648m.
To make an equivalent expression by combining like terms in the given expression, let's first identify the like terms. Like terms have the same variable(s) raised to the same power(s).
In the given expression, we have:
-3.252m and 9.9m, which are like terms because they both have the variable m raised to the power 1.
To combine these like terms, we can add their coefficients (numbers in front of the variables). The coefficient of -3.252m is -3.252 and the coefficient of 9.9m is 9.9.
So, the sum of -3.252m and 9.9m is -3.252m + 9.9m = (9.9 - 3.252)m = 6.648m.
Now, let's rewrite the original expression with the combined like terms:
4.4 - 3.252m + 9.9m + 8.4 = 4.4 + 6.648m + 8.4.
We can further combine the constant terms 4.4 and 8.4:
4.4 + 6.648m + 8.4 = (4.4 + 8.4) + 6.648m = 12.8 + 6.648m.
Therefore, an equivalent expression by combining like terms is 12.8 + 6.648m.