Answer:
x1=7,
x2=6
Step-by-step explanation:
x²-13x+42=0
a=1, b=-13, c=42
x1,2=(-b+-sqrt(b^2-4ac)) /2a
x1,2=(-(-13)+-sqrt((-13)^2-4*1*42))/2*1
x1,2=(13+-sqrt (169-168))/2
x1,2=(13+-sqrt(1))/2
x1,2=(13+-1)/2
x1=(13+1)/2, x2=(13-1)/2
x1=14/2, x2=12/2
x1=7, x2 =6
