Determine if the triangle is similar. if yes write which postulate proves that they are similar

Two blends of tea are mixed to make a blend that will be sold at the fair. black tea sells for $2.20 per pound and orange pekoe tea sells for $3.00 per pound. how much of each should be used to obtain a 4lb blend selling for $2.50 per pound?

If 3x+8=3x+8 is it one solution or no solution

Which shows the correct substitution of the values a, b and c from the equation 1=-2x+3x^2+1