To solve the equation \( x + 90 = 150 \), we can isolate \( x \) by subtracting 90 from both sides:
\[ x = 150 - 90 = 60 \]
Now we can interpret the second part of your statement. If you are estimating \( x \), you might round it or make an approximation. If, for example, you estimate \( x \) as 60 (exact) or a rough approximation close to it, if you are using a different estimation method, it might lead to different results.
If you are estimating \( 60 \) downwards (say to 50) or rounding it differently, we can expect that \( 50 + 90 = 140 \), which is less than \( 150 \).
So, if we are estimating \( x \) below its actual value, we can expect the estimate to be less than the actual sum.
Final response: We can expect the estimate to be less than the actual sum.