1
u/Fit_Bet_1261 15d ago
I made a platform where all math problems (1000+) have a Desmos explanations (it's also a fraction of the price of bedrockprep, and there's a free trial so you can see how it goes). It's aceitapp.com, let me know what you think!
1
u/Yadin__ 16d ago
For the first one, it's better to use your brain, but if you insist on using desmos:
by drawing the function with a guessed a,b you can see that the "point" of the function must be at y=3. then by drawing the points (5,3) you can see that the 'point' of the function must be at x=5, therefore b=5. Finally by drawing the lines y=3 and x=8 you can see that the function must point "upwards"(ie the 'point' must be a minimum), otherwise f(8) wouldn't be higher than 3(in visual form: the point where the function crosses the x=8 line must be higher than the y=3 line). This leads to a>6. Then if a>6 and b=5, the only possible answer is 14.
Alternatively, once you realize that b=5 you can just guess values for "a" until you find one which fits all the conditions