Brainliest to who get it right.

i know quadratic formula. i don’t understand how i would input the lines i’m given into that formula. me, i already know what x equals.

You know from the geometry of the problem that
.. 7^2 = y*(y +11)
.. 49 = y^2 +11y
.. y^2 +11y -49 = 0 . . . . . . . . the quadratic equation in standard form

Now, you're ready to use the quadratic formula. You have
.. a = 1
.. b = 11
.. c = -49
.. y = (-b ±√(b^2 -4ac))/(2a)
.. y = (-11 ±√(11^2 -4*1*(-49)))/(2*1) . . . . . substitute the values for a, b, c
.. = (-11 ±√317)/2 ≈ {-14.4, 3.4}

Since segment lengths can only be positive,
.. y ≈ 3.4 cm

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.