What is the answer? Please Help me. -1/2 (12v-20) + 4 = -12 - 8v

Martin likes to make flower bouquets that have 3 daffodils and 4 tulips per vase. a daffodil has a mass of d grams, a tulip has a mass of t grams, and the vase has a mass of u grams. the expression 5(3d + 4t + v) describes the mass of 5 bouquets. match each amount in the situation with the expression that represents it. situation expression number of bouquets mass of one bouquet mass of the tulips in one bouquet 4t mass of the daffodils in one bouquet 3d + 4t + v

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)