How do you estimate a percentage problem, for example 31% of 40

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36

The federal reserve controls certain interest rates in the united states. investors often try to speculate as to whether the federal reserve will raise or lower rates and by how much. suppose a company conducts extensive interviews with financial analysts, and as a result, predicts that "thefed" will increase rates by an average of 0.25 percentage points every six months for the forseeable future. which type of equation could be used to model the predicted interest rates over the next several years, assuming no other significant changes? a) a linear equation b) a quadratic equation c) a polynomial equation d) an exponential equation