CalcHack Try it free

What CalcHack gives you

One real SAT question, solved the way the app would solve it. No signup, nothing to install — this is just the output.

The question

If f(x) = 2x² − 7x + 3, what is the sum of the solutions of f(x) = 0?

⚡ Desmos is the fastest way here It shows both zeros instantly — no factoring, no quadratic formula, no sign mistakes.
QuadraticsMedium⏱ ~35 sec

Step by step

1

Graph the function

Type the function exactly as written. Desmos draws the parabola immediately — you're looking for where it crosses the x-axis.

y=2x^{2}-7x+3A parabola opening upward appears
-2-1123456-4-22468 (0.5, 0) (3, 0)
What you see: a blue U-shaped parabola dips below the x-axis, crossing it twice — once just right of 0 and once near x = 3.
2

Tap the zeros

Tap the curve, then tap the two grey points where it crosses the x-axis. Desmos labels them for you — those are your solutions.

(0.5,0)First zero, revealed by tapping the curve
(3,0)Second zero
What you see: two labelled points sitting exactly where the curve meets the axis.
3

Add them in Desmos

Type the sum on a new line. Desmos doubles as a scratchpad, so you never do arithmetic in your head under time pressure.

0.5+3= 3.5 — done
What you see: the row shows 0.5+3 with = 3.5 on the right. That's your answer.
Answer
3.5  (or 7/2)

The zeros are x = 0.5 and x = 3, so their sum is 3.5.

⚠ Common trap

Picking 1.5 — that's the product of the roots (c/a = 3/2), not the sum. The SAT offers both on purpose.

The algebra way, if you prefer

Vieta's formulas: sum of roots = −b/a = 7/2. Faster if you already remember it — about ten seconds. CalcHack tells you when that's true instead of pushing you to the calculator every time.

That took one photo

Point your camera at any SAT math question and get this back. Five free every day, no account needed to start.

Try it on your own question