Evaluate 𝑚 plus 𝑘, given that 𝑚 equals seven and 𝑘 equals 15.
We want to add 𝑚 and 𝑘 together. 𝑚 equals seven and 𝑘 equals 15. What we do now is substitute the seven for the 𝑚. We can write seven in place of the 𝑚. Our addition symbol doesn’t change. We just bring that down.
And then, we’ll substitute 15 for 𝑘. In place of the letter 𝑘 in our problem, we write 15. And then we add them together. Seven plus 15 equals 22. That means that, in this case, 𝑚 plus 𝑘 equals 22.